As modern integrated circuits shrink in size, the associated transistors shrink in size as well. In order to operate with predictable properties, transistor production focused initially on shrinking feature size of transistors. However, as the size of transistor features has approached atomic sizes, new transistor designs have been developed. Fin field effect transistors (FinFETs) are sometimes used to replace planar metal oxide semiconductor field effect transistors (MOSFETs), enabling greater transistor packing density while maintaining predictable device performance.
Traditionally, a planar transistor such as a MOSFET has a source and drain disposed in a semiconductor, with a gate disposed on the surface of the semiconductor between the source and drain. A FinFET has a channel region in a raised fin, with the gate insulator and gate contact covering one or more sides of the fin in a channel region. A source and drain may be formed on each side of the channel region.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the various embodiments and are not necessarily drawn to scale.